Air-heater and safety feature for same



Jan. 31, 1961 R. R. DUPLER 2,969,787

AIR-HEATER AND SAFETY FEATURE FOR SAME Filed July 27, 1959 2 Sheets-Sheet 1 5+1 9' a 3 INVENTOR.

RAYMOND R. DUPLER W MEL ATTORNEY Jan. 31, 1961 R. R. DUPLER AIR-HEATER AND SAFETY FEATURE FOR SAME 2 Sheets-Sheet 2 Filed July 27, 1959 INVENTOR. RAYMOND R. DUPLER ATTORNEY AIR-HEATER AND SAFETY FEATURE FOR SAL E Raymond B. Dupler, 744 Euclid Ave., Toledo, Ohio Filed July 27, 1959, Ser. No. 829,761

4 Claims. (Cl. 12692) This invention relates to a fluid fuel fired hot air furnace simulating in general appearance a wood burning fire place, such that one can look through glass panes to see the flames, and in this connection reference is made to my Patent 2,789,554, dated April 23, 1957, and entitled Fuel Burning Air Heating Apparatus, wherein a furnace of this type is shown.

In a furnace of this construction the logs or the like are enclosed in a heating chamber but are visible through glass windows. As a safety measure, it is important that in the event one or both of the windows becomes broken for any reason, the supply of fuel is shut off. It is thus the aim of this invention to provide means for instantly and automatically shutting off the fuel supply in the event one or both of the windows through which the flames are viewed, are broken and in this manner eliminate a danger hazard.

Another object is to produce an improved mounting for the windows which not only facilitates the installation of the glass panel but is relatively simple and inexpensive to produce and assemble.

A further object contemplates the incorporation in a shatterable window panel a portion of the electrical circuit controlling the fuel supply so that in the event the window is shattered, the circuit is broken resulting in instantaneous shutting off of the fuel to the burners.

Other objects and advantages of the invention will hereinafter appear and, for purposes of illustration but not of limitation, an embodiment of the invention is shown on the accompanying drawings, in which Figure 1 is the front elevation of the furnace, a portion being broken away to show the controls for the fuel supply line;

Figure 2 is a vertical sectional view substantially on the line 2--2 of Figure l; a

Figure 3 is a fragmentary view substantially on the line 3-3 of Figure 2 showing the window panel mounted in the front wall of the heating chamber;

Figure 4 is an enlarged fragmentary elevation of the window mounted in a door and disposed directly in front of and spaced from the window in the front wall of the heating chamber;

Figure 5 is an enlarged fragmentary sectional view substantially on the line 5-5 of Figure 3;

Figure 6 is an enlarged fragmentary sectional view substantially on the line 6-6 of Figure 4;

Figure 7 is an enlarged fragmentary sectional view substantially on the line 7-7 of Figure 4;

Figure 8 is a wiring diagram showing the electrical controls for the fuel supply line; and

Figure 9 is a somewhat diagrammatic view showing contact arms moveable with the latch arm so that when the latch is in latching position, the switch arms engage the contacts for establishing the electrical circuit, but when the latch is moved to open position, the circuit is broken.

The illustrated embodiment of the invention comprises a hot air furnace generally indicated at 10 which con- I 2,969,787 Patented Jan. 31, 1961 sists of an upright sheet metal housing 11 having a front wall 12 formed in the lower part thereof with a substantially rectangular opening which is covered by a door frame 13 hinged to the front wall 12 by hinges 14 and has a manual latch 16 at the opposite end. The door has a glass panel 15 of substantial size for viewing the gas logs as will hereinafter be described.

In this instance air is supplied to the housing 11 through a duct 17 entering the bottom. As indicated in Figure 2 there is a diagonal partition 18 which confines the air to be heated to the rear portion of the housing. It will be understood that the heated air passes upwardly from the inlet duct 17 and is heated and then passes either through a screen and frame 19 at the front of the housing providing a warm air outlet or to another room, for example, through a riser duct 20.

Disposed within the housing 11, a part being in rear of and a part in front of the diagonal partition 13, is a fire box 21 having a vertical front wall in which is disposed an opening bounded by a rectangular frame 22 of approximately the same size as the door frame 13 above described and disposed directly in rear thereof. Suitably mounted within the frame 22 is a glass panel 23 and in rear of the panel 23 and disposed within the fire box 21 are gas logs 24, the flame from which is visible from the outside of the furnace through the glass windows 15 and 23.

Manifestly the window 23 will become very hot due to its proximity to the gas logs 24 and, although the rear face of the window 15 will become relatively hot, the front of this window will not be objectionably hot.

Gas is fed to the legs 24 from the outside through a fuel inlet pipe 25. As shown there is a manual shut off valve 26 in the pipe 25 and adjacent thereto is the usual pressure regulator 27. Adjacent the pressure regulator is a pilotstat 28 as is usual in installations of this type. Adjacent the pilotstat 28 and disposed in the line is a high flame gas valve 29, which is solenoid-controlled and is of well known construction so that detail illustration and description thereof is not considered necessary. Adjacent the valve 29 is a venturi 30 and next adjacent thereto is a low flame gas valve 31 of a well known construction and which is also electrically controlled by a solenoid. The valve 31 is also of a well known type and since the detail construction forms no part of this invention, further description and illustration is not considered necessary. Suffice it to say that the valves 29 and 31 are maintained in open and operative position when electrical current passes therethrough.

Above the fire box 21 and in communication therewith is an air heating chamber 32 which may have a plurality of tubes or pipes providing a tortuous path for the products of combustion to pass to the smoke pipe 33 so that the air passing around the fire box and upwardly over the heating chamber and out through the screened opening 19 or up through the riser 20 will become properly heated.

In accordance with this invention the glass panels 23 and 15 are of a shatterable glass. Preferably these panels are of tempered plate glass such that upon impact a panel completely shatters into small fragments. One suitable plate glass for this purpose is sold by The Libbey-Owens-Ford Glass Company of Toledo, Ohio, under the trademark Tuffiex. As will be hereinafter described, the electrical current employed for the operation of the valves 29 and 31 as well as other controls normal to a gas fired furnace, pass through or over a portion of each of the glass panels 15 and 23. In this connection reference is made to the diagram on Figure 8 and it will be noted that secured to an edge of each of these panels in spaced relation are electrically conthose skilled in this art.

ductive clips 34 and 35. These clips are electrically connected with each other by a strip 36 of silver solder which is fused into the glass, enabling electrical current to flow from one clip to the other. Manifestly in the event either of the glass panels is shattered from impact or otherwise, the electrical connection will be broken because of the specific nature of this glass. As shown a lead 37 from a source of electric current passes successively through the panels 23 and 15 flowing from one clip to the adjacent clip through the silver solder strip 36 and after passing from the glass panel 15 the lead passes to the manual latch 16. As shown on Figure 9, the latch 16 is provided on the inside of the frame 13 with a pair of diametrically opposed switch arms 16:: and 16b, which, when the door is closed, are in engagement with contacts 16 respectively so that the circuit may be established. The switch arms turn with the latch 16 so that when the latch is turned to open the door, the

switch arms are moved away from the contacts 160, thereby breaking the circuit. This simple expedient is not shown in detail but will be readily understood by Thus it will be apparent that in the event that the latch 16 is turned for the purpose of opening the door containing the glass panel 15, the circuit will be broken. From the latch 16 the lead 37 extends first to the low flame gas valve 31 and then to a delayed action control 38 of a type well known in this art so that detailed illustration and description thereof is not considered necessary. From this control the lead 37 extends to the high flame gas valve 29 and then to a thermostat 39 disposed in a suitable spot within the room, this thermostat being connected to the other termiml of the hot line. The lead extending to the thermostat is indicated at 40 and the lead from the thermostat is indicated at 41, this lead extending to the low flame gas valve 31.

It is manifest from the above description that in the event either of the glass panels 15 or 23 is shattered, the circuit is broken and the fuel supply to the gas logs 24 is instantly shut off. Also as above described tampering with the manual latch 16 with the view of opening the door will also result in instantaneously shutting off the fuel supply.

Each of the panels 15 and 23 is mounted in such manner as to enable them to be installed without difiiculty and also to provide a simple and improved means for achieving this end readily and inexpensively. As shown the frame for the window panel 23 consists of an inner L-shaped frame member 42 which abuts against the inside of the front wall of the fire box 21 and has a flange 43 which abuts the opening in the fire box wall. Cooperating with the frame member 42 is an outer L-shaped rim 45, a series of bolt and nut assemblies 44 holding these parts together. A U-shaped asbestos packing 46 is disposed in the channel thus formed and into which the edge portion of the glass panel 23 fits, thereby to provide a heat insulating mounting for same.

The mounting for the glass panel 15 is illustrated on Figures 6 and 7. The edge of the opening in the front wall 12 of the housing is bent inwardly to provide a flange 47 extending completely about the opening. For the top edge of the glass panel and, as shown in Figure 6, there is a T-shaped frame member 48, the T-portion of which is disposed on the outside of the opening and has inwardly extending flange portions to abut against the wall 12 and glass 15 as shown. A strip of asbestos packing 49 is disposed between the upper portion of the T-memher and the adjacent portion of the wall 12. Cooperating with the frame member 48 is an L-shaped rim member 50 which abuts against the stem of the T and has a flange to abut against the glass panel 15. This member cooperates with the T member 48 to provide a pocket for receiving a U-shaped asbestos packing 51 which embraces the edge portion of the glass panel 15. For retaining the rim member 50 in position a series of cotter pins 52 are disposed on the outer side of the rim member, thereby providing a removable mounting for the rim member 50 and frame member 48.

For the sides and bottom edge portions of the glass panel 15, as shown in Figure 7, there is an outer rim member 53, which has inwardly extending flanges 54 and 55 for engaging respectively the glass panel 15 and the adjacent portion of the housing wall 12. An asbestos packing 56 is disposed between the lower portion of the rim member 53 and the wall 12. An integral -L-shaped flange 57 provides a pocket for receiving a U-shaped asbestos packing 58 which embracesthe edge portion of the glass panel 15.

Fro-m the above it will be apparent that the framing of the window panels is accomplished inexpensively and in such manner that the panels can be readily and conveniently installed in position of use. This is also important in the event that one or the other of the glass panels becomes shattered, enabling it to bequickly and conveniently replaced.

Numerous changes in details of construction, arrangement and operation may be effected without departing the appended claims.

What I claim is:

1. In a furnace of the character described having an open front heating chamber containing gas logs or the like the flames of which are viewed through the open front and a transparent panel covering the front opening of the heating chamber, the improvement which comprises shatterable tempered glass constituting the transparent panel, means controlling the flow of fuel to the gas logs including a normally closed valve adapted to be opened in response to electrical energization, and an electrical circuit including said valve and having a portion incorporated in the shatterable glass panel so that upon shattering of the panel the fuel supply is instantly shut off.

2. The organization as claimed in claim 1 in which said circuit portion is a short strip of electro-conductive material incorporated in an edge portion of the glass panel, and has terminal members engaging end portions of said strip.

3. The organization as claimed in claim 1 in which said circuit portion is a strip of silver fused into an edge of the glass panel, having terminal members of conductive material in contact with the ends of the silver strip respectively.

4. In a furnace of the character described having an open front heating chamber containing gas logs or the like the flames of which are viewed through the open front and a transparent panel covering the front opening of the heating chamber, the improvement which comprises shatterable tempered glass constituting the transparent panel, a hinge mounting for said glass panel, a manual latch to hold said panel closed and having electrical contact elements arranged to be engaged when the latch is in latching position, means controlling the flow of fuel to the gas logs including a normally closed valve adapt ed to be opened in response to electrical energization, and an electrical circuit passing through said valve, a portion of said glass panel, and through said latch contact elements, so that the fuel is automatically shut off by said valve in the event the glass panel is shattered or the latch is actuated from latching position.

References Cited in the file of this patent UNITED STATES PATENTS 535,100 Gill Mar. 5, 1895 2,089,653 Kiss Aug. 10, 1937 2,188,339 Dunham Jan. 30, 1940 2,538,492 Anderson et al. Jan. 16, 1951 2,604,313 Grantham July 22, 1952 2,747,568 Dupler May 29, 1956 

